Most modern diesel engines, particularly diesel engines for large tractor-trailer trucks, use fuel injectors to deliver a desired fuel charge to an engine cylinder. The fuel injector is a nozzle which injects fuel, atomized by forcibly pumping fuel through the nozzle at high pressure, directly into the main combustion chamber of each cylinder. A fuel injector, particularly a fuel injector for use with a diesel engine, is required to accurately discharge a quantity of fuel into a combustion chamber of an internal combustion engine over a wide range of engine operating conditions.
Various factors are involved in the design and optimization of a fuel injection system. The air/fuel (A/F) ratio in the combustion chamber is controlled to achieve the desired engine performance, emissions, drivability, and fuel economy. Additional considerations in design of a fuel injection system include maintenance costs, reliability, physical space constraints, and adequate sealing.
The assembly of fuel injectors onto a cylinder head typically requires the use of fuel injector clamps which hold down, and secure the injector into the cylinder head. With demand for increase efficiencies of internal combustion engines, the number of valves that service a cylinder has increased. The fuel injection unit must be able to reside within the cluster of valves servicing the cylinder. Existing devices tend to be bulky, thereby adding to the crowding of components in the limited space on a cylinder head.
Prior art clamp arrangements include one bolt clamp with an injector hold down arm and a reaction force arm, and dual bolt clamps.
The present inventor has recognized that single bolt clamps allow for a slide-on clamping mechanism, however, the load and stresses experienced by the clamp is quite high. Dual bolt designs lowers the stress in the clamp, allows for more even loading of the fuel injector and the use of smaller bolts due to a lower required clamping force. However, with dual bolt designs, the clamp must be assembled on the injector, leading to more complex injector assembly and disassembly and thus, higher replacement costs.
The present inventor has recognized the need for a fuel injector clamp which encompasses the benefits of the dual bolt designs, without the need to assemble the clamp to the fuel injector.
The present inventor has recognized the need for a fuel injector clamp assembly that reduces loading and stress in the clamp, thus extending clamp lifespan and allowing a margin for increased loading on the injector if necessary.
The present inventor has recognized the need for a fuel injector clamp assembly that is less bulky and more suitable for use with cylinder heads with multiple valves.
The present inventor has recognized the need for a fuel injector assembly with a reduction in weight.